Atomizer for oil burners



Nov. 14, 1950 E. c. SMITH 2,530,269

ATOMIZER FOR QIiL BURNERS Filed Feb. 16, 1946 Ira/enter. O N

Patented Nov. 14, 1950 UNITED STATES PATENT OFFICE ATOMIZER FOR OILBURNERS Eric Colin Smith, Toronto, Ontario, Canada Application February16, 1946, Serial No. 648,101

2 Claims.

Y'Ihisinvention relates to improvements in devicesfor :atomizing oil forcombustion purposes and the principal object of the invention is toeffect a very uniform atomization of the oil and the admixture therewithof air in such a manner as to produce practically complete combustion soas to enable the use of the heat produced by such combustion in thedirect heating of baking ovens or the like.

A.further object of this invention is to provide an atomizer ofextremely simple and inexpensive construction which may be easilyadjusted to produce accurate results in the combustion of the particulartype of fuel being used.

The principal feature of this invention consists in the novelconstruction of a tubular member conducting the supply of oil to thedischarge whereby jetsof air under pressure are projected into the oilstream adjacent to the discharge and of saidoiltube and the oil streamis divided and projected into an annulus of air flowing past thedischarge end of. said tube which is guided by a.

taken from the area surrounding the tube is di- 1 rected throughorifices in the tube arranged in acute angular relation to the axis ofsaid tube adjacent to its delivery point.

In the accompanying drawings Figure l is a.

part longitudinal sectional elevational View of an oil atomizerconstructed in accordance with this invention. a

.Figure 2 is a perspective detail of the .spider means for accuratelycentering theoil delivery tube in its associated air nozzle.

Figure 3 is an enlarged longitudinal sectional view of the air nozzlestructure showing the oil delivery tube in elevation.

' Figure 4 is a much enlarged sectional detail of the'delivery end ofthe oil tube.

Referring to the accompanying drawings, in Figure 1 is shown a circularcasing I which is preferably provided with a tangentially arranged inlet2. This casing is provided with centrally arranged bosses 3 and4on itsopposite sidesand saidbosses are provided with threaded openings 5 and 6respectively.

A nut l is threaded into the top opening 5 and an oil feed pipe 8 isthreaded into a central orifice in the nut.

An oil feed nozzle tube 9 extends axially through the threaded opening 6and its extremity 2- which extends well beyond the boss 4 is formed withan outside taper I0- A plurality of small holes I I are formed in thewall of the nozzle tube 9 to extend angularly inwardly therethrough atan acute angle to the axis. The outer ends of these holes I I preferablyform fluted recesses I2 in the outer periphery of the tube at a pointadjacent to the tapered end I0 and the holes extend inwardly to cut intoand form fluted recesses I3 on the inner side of the tube. This fiutingarrangement of the holes in the middle of the tube 9 is extremelyimportant as will hereinafter appear.

A cylindrical casing member I4 threaded to fit into the threaded orifice6 has its inner wall spaced from the exteriorof the oil feed nozzle tube9 and the extremity of this central orifice in the casing I4 is formedwith an inwardly converging surface I5 terminating in a circular orificeI6, the latter being slightly larger than the outside diameter of theterminal end of the tapered portion III of the tube 9 which thus formsan annular throat around the. tapered end of the nozzle tube for thedischarge of an annulus of air around said nozzle.

The member I4 is of course adjustable in the threaded boss 4,consequently the converging inner wall may be adjusted relative to thetapered end of the nozzle tube and a suitable lock nut I1 is provided onthe-threaded exterior of the member I4 to hold it in adjusted positions.

It is important that the oil feed nozzle tube 9 should be maintainedconcentric with the air discharge orifice Ifi in the member I4 and inorder toensure this condition a sleeve I8 is mounted, preferably with asnug fit, upon the tube 9; and radial wings I9 extend outwardly fromthis sleeve to engage in close fitting contact with the interior wall ofthe cylindrical member I4.

These wings project downwardly beyond the end of the tube I8 and havetheir lower ends 20 bevelled to engage the bevelled surface I5 adjacentto the orifice I6. 7

The spaces between the wings I9 provide ducts permitting air from theinterior of the chamber I to flow freely past the sleeve I8 and aroundthe perforated end of the tube 9.

.Both the air and oil are delivered under pressure to the chamber I andtube 9 respectively and suitable control valves (not shown) will beprovided.

It will be understood that a greater volume of air is required than thevolume of oil and the feeds to these members will operate underdiffering pressures.

The flow of air through the member l4 being under higher pressure thanthe oil will force its way into the holes [I and as these are directedinwardly through the oil tube at an acute angle to the axis and both theentrance on the outside and the exit on the inside of the tube arefluted, the air will flow with the least amount of obstruction.Consequently a plurality of small streams of air are projected angularlyinwardly to the bore ofthe tube 9 in acute angulardirection to the axisof the tube, and they thus mingle with the oil at lesser pressure andbreak up the, body of the stream, thus applying a higher pres" sure tothe oil being emitted from the tube 9 at its discharge end.

This mixed stream of air and oil has a tendency to expand on release ofthe tube and it is further broken up by the flow of air of the annularpassage formed between the bevelled end of the tube 9 and the dischargeorifice [6.

It will be understood that steam may be used in place of air if desiredor a combination of air and steam and the impinging action of the highpressure air striking the partially atomized oil being emitted from thenozzle of the tube 9 is atomized to produce a finely atomizedcombustible mixture. I

The resultant atomized oil and air emitted from a nozzle constructed asherein described maybe burned directly but it is preferably projectedinto a suitable form of tuyere which results in a further mixture of airand with proper adjustment of the air and oil supply and adjustment ofthe nozzle relative to the tuyere a flame is produced which burns withsubstantially complete combustion, eliminating carbon deposits withinthe chamber to which the products of combustion are directed.

It will be readily understood that the operation of this burner may beenhanced and a further fractionating effect produced with the atomizedoil by the use of a tuyere of refractory ma terial which will retainconsiderable heat and add to the gasifying of the combustible material.

When such conditions are observed radiant heat free from flamemay beintroducedinto the chamber to be heated and practical results have beenobtained in the application of this heat directly to baking ovensandbakery products can be produced free from deposits of any kind or fromany detrimental effect of gases;

The construction of this burner is extremely simple. It can bemanufactured to produce exceptional results with either Bunker C oil orlighter fuel oil.

What I claim as my invention is: 1. An atomizer for oilburners-comprising air pressure chamber, a pressure air tube extendingfrom said chamber and having a cylindrical interior terminating in aconvergent end having a cylindrical discharge orifice there through, apressure oil tube extending throughsaid air pressure chamber and saidpressure air tube said oil and air tubes being'relatively adjustablelongitudinally, means for maintaining said oil tube concentric withinsaid air tube, said oil tube having a converging tip terminating withinthe discharge orifice of said air tube defining therewith a divergingannular passage around said oil tube tip having restricted communicationwith the interior of said air tube, said air and oil tubes in relativelongitudinal adjustment providing for regulation of flow passage area tosaid divergent annular passage from said air tube while correspondinglyregulating flow passage area throughout said diverging annular passage,the wall of the converging tip of said oil tube being. formed with aplurality of inwardly converging passages whereby air under pressureregulated in accordance with regulation of flow passage area to saiddivergent annular passage is conveyed from the convergent end of saidair tube into said oil tube to provide initial atomization of oilreaching said converging tube tip while such oil is held from expansionwithin said oil tube tip and other air under pressure is conveyed fromthe convergent end of said air tube as an annular stream directedthrough said diverging annular passage past the converging tip of saidoil tube to provide further atomization of oil and air expelledtherefrom to expand into the path of said annular air stream.

2. An atomizer device comprising a pressure air chamber, a pressure airtube extending from said chamber and having a cylindrical interiorterminating in a convergent end having a cylindrical discharge orificetherethrough, a liquid tube extending through said air pressure chamberand tube, said liquid and air tubes being relatively adjustablelongitudinally, means maintaining said tubes concentric, meansmaintaining said tubes in relative longitudinal adjustment, said liquidtube having a convergent tip terminating within the discharge orifice ofsaid air tube defining therewith a diverging annular expansion passagehaving a restricted entrance providing communication with said airchamber, said tubes in relative longitudinal adjustment providing forregulation of flow passage area of said restricted entrance whilesimultaneously and correspondingly regulating flow passage areathroughout said expansion passage, the wall of the convergent tip ofsaid liquid tube being formed with a plurality of inwardly convergingpassages to direct pressure air into said liquid tube ahead of therestricted entrance with other pressure air passing through saidentrance being expanded gradually in said expansion passage to issuefrom said discharge orifice as an annular air stream of substantialcross section.

ERIC COLIN SMITH.

EFERENCES CITED The following references are of recordin the file ofthis patent:

UNITED STATES PATENTS 'Morrell Jan. 30, 1945

